No treatment is available for most of these disorders. Mannose supplementation relieves the symptoms in PMI-CDG (CDG-Ib) for the most part, even though the hepatic fibrosis may persist. Fucose supplementation has had a partial effect on some SLC35C1-CDG (CDG-IIc or LAD-II) patients.

Surgical excision is performed when exostoses lead to growth disturbances or lead to disability. Knee osteotomies are associated with high incidence of peroneal nerve paralysis.

Surgery, physical therapy and pain management are currently the only options available to HME patients, but success varies from patient to patient and many struggle with pain, fatigue and mobility problems throughout their lives.

It is not uncommon for HME patients to undergo numerous surgical procedures throughout their lives to remove painful or deforming exostoses, correct limb length discrepancies or improve range of motion. Usually the treatment can be problematic. The osteochondromas can return in the same places and may be more painful.

In terms of treatment, acute hypoglycemia is reversed by raising the blood glucose, but in most forms of congenital hyperinsulinism hypoglycemia recurs and the therapeutic effort is directed toward preventing falls and maintaining a certain glucose level. Some of the following measures are often tried:

Corn starch can be used in feeding; unexpected interruptions of continuous feeding regimens can result in sudden, hypoglycemia, gastrostomy tube insertion (requires a minor surgical procedure) is used for such feeding.Prolonged glucocorticoid use incurs the many unpleasant side effects of Cushing's syndrome, while diazoxide can cause fluid retention requiring concomitant use of a diuretic, and prolonged use causes hypertrichosis. Diazoxide works by opening the K channels of the beta cells. Octreotide must be given by injection several times a day or a subcutaneous pump must be inserted every few days, octreotide can cause abdominal discomfort and responsiveness to octreotide often wanes over time. Glucagon requires continuous intravenous infusion, and has a very short "half life".

Nifedipine is effective only in a minority, and dose is often limited by hypotension.

Pancreatectomy (removal of a portion or nearly all of the pancreas) is usually a treatment of last resort when the simpler medical measures fail to provide prolonged normal blood sugar levels. For some time, the most common surgical procedure was removal of almost all of the pancreas, this cured some infants but not all. Insulin-dependent diabetes mellitus commonly develops, though in many cases it occurs many years after the pancreatectomy.Later it was discovered that a sizeable minority of cases of mutations were focal, involving overproduction of insulin by only a portion of the pancreas. These cases can be cured by removing much less of the pancreas, resulting in excellent outcomes with no long-term problems.

A congenital disorder of glycosylation (previously called carbohydrate-deficient glycoprotein syndrome) is one of several rare inborn errors of metabolism in which glycosylation of a variety of tissue proteins and/or lipids is deficient or defective. Congenital disorders of glycosylation are sometimes known as CDG syndromes. They often cause serious, sometimes fatal, malfunction of several different organ systems (especially the nervous system, muscles, and intestines) in affected infants. The most common subtype is CDG-Ia (also referred to as PMM2-CDG) where the genetic defect leads to the loss of phosphomannomutase 2, the enzyme responsible for the conversion of mannose-6-phosphate into mannose-1-phosphate.

De Barsy syndrome is a rare autosomal recessive genetic disorder. Symptoms include cutis laxa (loose hanging skin) as well as other eye, musculoskeletal, and neurological abnormalities. It is usually progressive, manifesting side effects that can include clouded corneas, cataracts, short stature, dystonia, or progeria (premature aging).

It was first described in 1967 by De Barsy et al. and, as of 2011, there have been 27 cases reported worldwide. The genes that cause De Barsy syndrome have not been identified yet, although several studies have narrowed down the symptoms' cause. A study by Reversade et al. has shown that a mutation in PYCR1, the genetic sequence that codes for mitochondrial enzymes that break down proline, are prevalent in cases of autosomal recessive cutis laxa (ARCL), a condition very similar to De Barsy syndrome. A study by Leao-Teles et al. has shown that De Barsy syndrome may be related to mutations in ATP6V0A2 gene, known as ATP6V0A2-CDG by the new naming system.

Alternative names for De Barsy syndrome include corneal clouding-cutis laxa-mental retardation, cutis laxa-growth deficiency syndrome, De Barsy–Moens–Diercks syndrome, and progeroid syndrome of De Barsy.

Some parents of children with MHE have observed autism-like social problems in their children. To explore those observations more deeply, a 2012 study by the Sanford-Burnham Medical Research Institute used a mouse model of MHE to observe cognitive function. The findings indicated that the mutant mice endorsed three autistic characteristics: social impairment, impairments in ultrasonic vocalization, and repetitive behavior.

Congenital hyperinsulinism is a medical term referring to a variety of congenital disorders in which hypoglycemia is caused by excessive insulin secretion. Congenital forms of hyperinsulinemic hypoglycemia can be transient or persistent, mild or severe. These conditions are present at birth and most become apparent in early infancy. Mild cases can be treated by frequent feedings, more severe cases can be controlled by medications that reduce insulin secretion or effects